This paper presents the search for the production of a Higgs boson in association with a single top quark (tHq), using data collected in proton-proton collisions at a center-of-mass energy of 8TeV corresponding to an integrated luminosity of 19.7 fb(-1). The search exploits a variety of Higgs boson decay modes resulting in final states with photons, bottom quarks, and multiple charged leptons, including tau leptons, and employs a variety of multivariate techniques to maximize sensitivity to... Show moreThis paper presents the search for the production of a Higgs boson in association with a single top quark (tHq), using data collected in proton-proton collisions at a center-of-mass energy of 8TeV corresponding to an integrated luminosity of 19.7 fb(-1). The search exploits a variety of Higgs boson decay modes resulting in final states with photons, bottom quarks, and multiple charged leptons, including tau leptons, and employs a variety of multivariate techniques to maximize sensitivity to the signal. The analysis is optimized for the opposite sign of the Yukawa coupling to that in the standard model, corresponding to a large enhancement of the signal cross section. In the absence of an excess of candidate signal events over the background predictions, 95% confidence level observed (expected) upper limits on anomalous tHq production are set, ranging between 600 (450) fb and 1000 (700) fb depending on the assumed diphoton branching fraction of the Higgs boson. This is the first time that results on anomalous tHq production have been reported. Show less

Date Issued

2016-06-30

Identifier

FSU_libsubv1_wos_000379505300001, 10.1007/JHEP06(2016)177

Format

Citation

Title

Measurements Of T(t)over-bar Spin Correlations And Top Quark Polarization Using Dilepton Final States In Pp Collisions At Root S=8 Tev.

Measurements of the top quark-antiquark (t (t) over bar) spin correlations and the top quark polarization are presented for t (t) over bar pairs produced in pp collisions at root s = 8 TeV. The data correspond to an integrated luminosity of 19.5 fb(-1) collected with the CMS detector at the LHC. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom... Show moreMeasurements of the top quark-antiquark (t (t) over bar) spin correlations and the top quark polarization are presented for t (t) over bar pairs produced in pp collisions at root s = 8 TeV. The data correspond to an integrated luminosity of 19.5 fb(-1) collected with the CMS detector at the LHC. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom quark. The spin correlations and polarization are measured from the angular distributions of the two selected leptons, both inclusively and differentially, with respect to the invariant mass, rapidity, and transverse momentum of the t (t) over bar system. The measurements are unfolded to the parton level and found to be in agreement with predictions of the standard model. A search for new physics in the form of anomalous top quark chromo moments is performed. No evidence of new physics is observed, and exclusion limits on the real part of the chromo-magnetic dipole moment and the imaginary part of the chromo-electric dipole moment are evaluated. Show less

Date Issued

2016-03-09

Identifier

FSU_libsubv1_wos_000371742000002, 10.1103/PhysRevD.93.052007

Format

Citation

Title

Multiplicity And Rapidity Dependence Of Strange Hadron Production In Pp, Ppb, And Pbpb Collisions At The Lhc.

Measurements of strange hadron (K-S(0), Lambda +(Lambda) over bar, and Xi(-)+(Xi) over bar (+)) transverse momentum spectra in pp, pPb, and PbPb collisions are presented over a wide range of rapidity and event charged-particle multiplicity. The data were collected with the CMS detector at the CERN LHC in pp collisions at root s= 7 TeV, pPb collisions at root(NN)-N-s= 5.02 TeV, and PbPb collisions at root(NN)-N-s = 2.76 TeV. The average transverse kinetic energy is found to increase with... Show moreMeasurements of strange hadron (K-S(0), Lambda +(Lambda) over bar, and Xi(-)+(Xi) over bar (+)) transverse momentum spectra in pp, pPb, and PbPb collisions are presented over a wide range of rapidity and event charged-particle multiplicity. The data were collected with the CMS detector at the CERN LHC in pp collisions at root s= 7 TeV, pPb collisions at root(NN)-N-s= 5.02 TeV, and PbPb collisions at root(NN)-N-s = 2.76 TeV. The average transverse kinetic energy is found to increase with multiplicity, at a faster rate for heavier strange particle species in all systems. At similar multiplicities, the difference in average transverse kinetic energy between different particle species is observed to be larger for pp and pPb events than for PbPb events. In pPb collisions, the average transverse kinetic energy is found to be slightly larger in the Pb-going direction than in the p-going direction for events with large multiplicity. The spectra are compared to models motivated by hydrodynamics. (c) 2017 The Author(s). Published by Elsevier B.V. Show less

Date Issued

2017-05-10

Identifier

FSU_libsubv1_wos_000400677700015, 10.1016/j.physletb.2017.01.075

Format

Citation

Title

Measurement of [Formula: see text] production with additional jet activity, including [Formula.

Jet multiplicity distributions in top quark pair ([Formula: see text]) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7[Formula: see text]. The measurement is performed in the dilepton decay channels ([Formula: see text], [Formula: see text], and [Formula: see text]). The absolute and normalized differential cross sections for [Formula: see text] production are measured... Show moreJet multiplicity distributions in top quark pair ([Formula: see text]) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7[Formula: see text]. The measurement is performed in the dilepton decay channels ([Formula: see text], [Formula: see text], and [Formula: see text]). The absolute and normalized differential cross sections for [Formula: see text] production are measured as a function of the jet multiplicity in the event for different jet transverse momentum thresholds and the kinematic properties of the leading additional jets. The differential [Formula: see text] and [Formula: see text] cross sections are presented for the first time as a function of the kinematic properties of the leading additional [Formula: see text] jets. Furthermore, the fraction of events without additional jets above a threshold is measured as a function of the transverse momenta of the leading additional jets and the scalar sum of the transverse momenta of all additional jets. The data are compared and found to be consistent with predictions from several perturbative quantum chromodynamics event generators and a next-to-leading order calculation. Show less

A search is presented for the production of two Higgs bosons in final states containing two photons and two bottom quarks. Both resonant and nonresonant hypotheses are investigated. The analyzed data correspond to an integrated luminosity of 19.7 fb(-1) of proton-proton collisions at root s = 8 TeV collected with the CMS detector. Good agreement is observed between data and predictions of the standard model (SM). Upper limits are set at 95% confidence level on the production cross section of... Show moreA search is presented for the production of two Higgs bosons in final states containing two photons and two bottom quarks. Both resonant and nonresonant hypotheses are investigated. The analyzed data correspond to an integrated luminosity of 19.7 fb(-1) of proton-proton collisions at root s = 8 TeV collected with the CMS detector. Good agreement is observed between data and predictions of the standard model (SM). Upper limits are set at 95% confidence level on the production cross section of new particles and compared to the prediction for the existence of a warped extra dimension. When the decay to two Higgs bosons is kinematically allowed, assuming a mass scale Lambda(R) = 1 TeV for the model, the data exclude a radion scalar at masses below 980 GeV. The first Kaluza-Klein excitation mode of the graviton in the RS1 Randall-Sundrum model is excluded for masses between 325 and 450 GeV. An upper limit of 0.71 pb is set on the nonresonant two-Higgs-boson cross section in the SM-like hypothesis. Limits are also derived on nonresonant production assuming anomalous Higgs-boson couplings. Show less

Date Issued

2016-09-29

Identifier

FSU_libsubv1_wos_000385966000001, 10.1103/PhysRevD.94.052012

Format

Citation

Title

Search For R-parity Violating Decays Of A Top Squark In Proton-proton Collisions At Root S=8tev.

The results of a search for a supersymmetric partner of the top quark (top squark), pair-produced in proton-proton collisions at root s = 8 TeV, are presented. The search, which focuses on R-parity violating, chargino-mediated decays of the top squark, is performed in final states with low missing transverse momentum, two oppositely charged electrons or muons, and at least five jets. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb(-1)collected with the CMS... Show moreThe results of a search for a supersymmetric partner of the top quark (top squark), pair-produced in proton-proton collisions at root s = 8 TeV, are presented. The search, which focuses on R-parity violating, chargino-mediated decays of the top squark, is performed in final states with low missing transverse momentum, two oppositely charged electrons or muons, and at least five jets. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb(-1)collected with the CMS detector at the LHC in 2012. The data are found to be in agreement with the standard model expectation, and upper limits are placed on the top squark pair production cross section at 95% confidence level. Assuming a 100% branching fraction for the top squark decay chain, (t) over tilde -> t (chi) over tilde (+/-)(1), (chi) over tilde (+/-)(1) -> l(+/-) + jj, top squark masses less than 890(1000) GeV for the electron (muon) channel are excluded for the first time in models with a single nonzero R-parity violating coupling. lambda'(ijk) (i, j, k <= 2), where i, j, k correspond to the three generations. (C) 2016 The Author(s). Published by Elsevier B.V. Show less

Date Issued

2016-09-10

Identifier

FSU_libsubv1_wos_000382890500029, 10.1016/j.physletb.2016.06.039

Format

Citation

Title

Relative Modification Of Prompt Psi(2s) And J/psi Yields From Pp To Pbpb Collisions At Root(s)(nn)=5.02 Tev.

The relative modification of the prompt psi(2S) and J/psi yields from pp to PbPb collisions, at the center-of- mass energy of 5.02 TeV per nucleon pair, is presented. The analysis is based on pp and PbPb data samples collected by the CMS experiment at the LHC in 2015, corresponding to integrated luminosities of 28.0 pb(-1) and 464 mu b(-1), respectively. The double ratio of measured yields of prompt charmonia reconstructed through their decays into muon pairs,(N-psi(2S)/N J/psi )(PbPb)/(N-psi... Show moreThe relative modification of the prompt psi(2S) and J/psi yields from pp to PbPb collisions, at the center-of- mass energy of 5.02 TeV per nucleon pair, is presented. The analysis is based on pp and PbPb data samples collected by the CMS experiment at the LHC in 2015, corresponding to integrated luminosities of 28.0 pb(-1) and 464 mu b(-1), respectively. The double ratio of measured yields of prompt charmonia reconstructed through their decays into muon pairs,(N-psi(2S)/N J/psi )(PbPb)/(N-psi((2S))/N (J/psi) )(pp),is determined as a function of PbPb collision centrality and charmonium transverse momentum p(T), in two kinematic intervals: broken vertical bar y vertical bar < 1.6 covering 6.5 < pT < 30 GeV/c and 1.6 < broken vertical bar y vertical bar < 2.4 covering 3 < pT < 30 GeV/c. The centrality-integrated double ratios are 0.36 +/- 0.08(stat) +/- 0.05(syst) in the first interval and 0.24 +/- 0.22(stat) +/- 0.09(syst) in the second. The double ratio is lower than unity in all the measured bins, suggesting that the psi(2S) yield is more suppressed than the J/psi yield in the explored phase space. Show less

Date Issued

2017-04-20

Identifier

FSU_libsubv1_wos_000399817600002, 10.1103/PhysRevLett.118.162301

Format

Citation

Title

Observation Of Gamma(1s) Pair Production In Proton-proton Collisions At Root S=8 Tev.

Pair production of gamma(1S) mesons is observed at the LHC in proton-proton collisions at root s = 8 TeV by the CMS experiment in a data sample corresponding to an integrated luminosity of 20.7 fb(-1). Both gamma(1S) candidates are fully reconstructed via their decays to mu(+) mu(-). The fiducial acceptance region is defined by an absolute gamma(1S) rapidity smaller than 2.0. The fiducial cross section for the production of gamma(1S) pairs, assuming that both mesons decay isotropically, is... Show morePair production of gamma(1S) mesons is observed at the LHC in proton-proton collisions at root s = 8 TeV by the CMS experiment in a data sample corresponding to an integrated luminosity of 20.7 fb(-1). Both gamma(1S) candidates are fully reconstructed via their decays to mu(+) mu(-). The fiducial acceptance region is defined by an absolute gamma(1S) rapidity smaller than 2.0. The fiducial cross section for the production of gamma(1S) pairs, assuming that both mesons decay isotropically, is measured to be 68.8 +/- 12.7 (stat) +/- 7.4 (syst) +/- 2.8 (B) pb, where the third uncertainty comes from the uncertainty in the branching fraction of gamma(1S) decays to mu(+) mu(-). Assuming instead that the gamma(1S) mesons are produced with different polarizations leads to variations in the measured cross section in the range from 38% to +36%. Show less

Date Issued

2017-05-03

Identifier

FSU_libsubv1_wos_000400871100001, 10.1007/JHEP05(2017)013

Format

Citation

Title

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks.

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons ([Formula: see text]) in proton-proton collisions collected by the CMS experiment at the LHC at [Formula: see text]. The data correspond to an integrated luminosity of 19.7[Formula: see text]. The search considers [Formula: see text] resonances with masses between 1 and 3[Formula: see text], having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization... Show moreA search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons ([Formula: see text]) in proton-proton collisions collected by the CMS experiment at the LHC at [Formula: see text]. The data correspond to an integrated luminosity of 19.7[Formula: see text]. The search considers [Formula: see text] resonances with masses between 1 and 3[Formula: see text], having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and [Formula: see text] events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 % confidence level for the product of the production cross section and branching fraction [Formula: see text] range from 10 to 1.5[Formula: see text] for the mass of X from 1.15 to 2.0[Formula: see text], significantly extending previous searches. For a warped extra dimension theory with a mass scale [Formula: see text] [Formula: see text], the data exclude radion scalar masses between 1.15 and 1.55[Formula: see text]. Show less

The nuclear modification factor [Formula: see text] and the azimuthal anisotropy coefficient [Formula: see text] of prompt and nonprompt (i.e. those from decays of b hadrons) [Formula: see text] mesons, measured from PbPb and pp collisions at [Formula: see text] [Formula: see text] at the LHC, are reported. The results are presented in several event centrality intervals and several kinematic regions, for transverse momenta [Formula: see text] [Formula: see text] and rapidity [Formula: see... Show moreThe nuclear modification factor [Formula: see text] and the azimuthal anisotropy coefficient [Formula: see text] of prompt and nonprompt (i.e. those from decays of b hadrons) [Formula: see text] mesons, measured from PbPb and pp collisions at [Formula: see text] [Formula: see text] at the LHC, are reported. The results are presented in several event centrality intervals and several kinematic regions, for transverse momenta [Formula: see text] [Formula: see text] and rapidity [Formula: see text], extending down to [Formula: see text] [Formula: see text] in the [Formula: see text] range. The [Formula: see text] of prompt [Formula: see text] is found to be nonzero, but with no strong dependence on centrality, rapidity, or [Formula: see text] over the full kinematic range studied. The measured [Formula: see text] of nonprompt [Formula: see text] is consistent with zero. The [Formula: see text] of prompt [Formula: see text] exhibits a suppression that increases from peripheral to central collisions but does not vary strongly as a function of either or [Formula: see text] in the fiducial range. The nonprompt [Formula: see text] [Formula: see text] shows a suppression which becomes stronger as rapidity or [Formula: see text] increases. The [Formula: see text] and [Formula: see text] of open and hidden charm, and of open charm and beauty, are compared. Show less

A search for narrow resonances in proton-proton collisions at root s = 13 TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4 fb(-1). The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1... Show moreA search for narrow resonances in proton-proton collisions at root s = 13 TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4 fb(-1). The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string resonances with masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV, and W' bosons below 2.6 TeV. These results significantly extend previously published limits. Show less

Date Issued

2016-02-18

Identifier

FSU_libsubv1_wos_000370621200009, 10.1103/PhysRevLett.116.071801

Format

Citation

Title

Suppression And Azimuthal Anisotropy Of Prompt And Nonprompt J/psi Production In Pbpb Collisions At Root S-nn=2.76 Tev.

The nuclear modification factor R-AA and the azimuthal anisotropy coefficient v(2) ofprompt and nonprompt (i.e. those from decays of b hadrons) J/psi mesons, measured from PbPb and pp collisions at root S-NN = 2.76 rfeV at itheLHC, are reported. The results are presented in several event centrality intervals and several kinematic regions, for transverse momenta p(T) > 6.5 GeV/c and rapidity vertical bar y vertical bar
Show moreThe nuclear modification factor R-AA and the azimuthal anisotropy coefficient v(2) ofprompt and nonprompt (i.e. those from decays of b hadrons) J/psi mesons, measured from PbPb and pp collisions at root S-NN = 2.76 rfeV at itheLHC, are reported. The results are presented in several event centrality intervals and several kinematic regions, for transverse momenta p(T) > 6.5 GeV/c and rapidity vertical bar y vertical bar < 2.4, extending down to p(T) = 3 GeV/c in the 1.6 < vertical bar y vertical bar < 2.4 range. The v(2) of prompt J/psi is found to be nonzero, but with no strong dependence on centrality, rapidity, or p(T) over the full kinematic range studied. The measured v(2) of nonprompt J/psi is consistent with zero. The R-AA of prompt J/psi exhibits a suppression that increases from peripheral to central collisions but does not vary strongly as a function of either y or pT in the fiducial range. The nonprompt J/psi RAA shows a suppression which becomes stronger as rapidity or p(T) increases. The v(2) and R-AA of open and hidden charm, and of open charm and beauty, are compared. Show less

Date Issued

2017-04-19

Identifier

FSU_libsubv1_wos_000399833700003, 10.1140/epjc/s10052-017-4781-1

Format

Citation

Title

Measurement of dijet azimuthal decorrelation in pp collisions at [Formula: see text]..

A measurement of the decorrelation of azimuthal angles between the two jets with the largest transverse momenta is presented for seven regions of leading jet transverse momentum up to 2.2[Formula: see text]. The analysis is based on the proton-proton collision data collected with the CMS experiment at a centre-of-mass energy of 8[Formula: see text] corresponding to an integrated luminosity of 19.7[Formula: see text]. The dijet azimuthal decorrelation is caused by the radiation of additional... Show moreA measurement of the decorrelation of azimuthal angles between the two jets with the largest transverse momenta is presented for seven regions of leading jet transverse momentum up to 2.2[Formula: see text]. The analysis is based on the proton-proton collision data collected with the CMS experiment at a centre-of-mass energy of 8[Formula: see text] corresponding to an integrated luminosity of 19.7[Formula: see text]. The dijet azimuthal decorrelation is caused by the radiation of additional jets and probes the dynamics of multijet production. The results are compared to fixed-order predictions of perturbative quantum chromodynamics (QCD), and to simulations using Monte Carlo event generators that include parton showers, hadronization, and multiparton interactions. Event generators with only two outgoing high transverse momentum partons fail to describe the measurement, even when supplemented with next-to-leading-order QCD corrections and parton showers. Much better agreement is achieved when at least three outgoing partons are complemented through either next-to-leading-order predictions or parton showers. This observation emphasizes the need to improve predictions for multijet production. Show less

The process pp -> pl(+)l(-)p(()*()), with l(+)l(-) a muon or an electron pair produced at midrapidity with mass larger than 110 GeV, has been observed for the first time at the LHC in pp collisions at root s = 13 TeV. One of the two scattered protons is measured in the CMS-TOTEM precision proton spectrometer (CT-PPS), which operated for the first time in 2016. The second proton either remains intact or is excited and then dissociates into a low-mass state p*, which is undetected. The... Show moreThe process pp -> pl(+)l(-)p(()*()), with l(+)l(-) a muon or an electron pair produced at midrapidity with mass larger than 110 GeV, has been observed for the first time at the LHC in pp collisions at root s = 13 TeV. One of the two scattered protons is measured in the CMS-TOTEM precision proton spectrometer (CT-PPS), which operated for the first time in 2016. The second proton either remains intact or is excited and then dissociates into a low-mass state p*, which is undetected. The measurement is based on an integrated luminosity of 9.4 fb(-1) collected during standard, high-luminosity LHC operation. A total of 12 mu(+)/mu(-) and 8 e(+)e(-) pairs with m(l(+)l(-)) > 110 GeV, and matching forward proton kinematics, are observed, with expected backgrounds of 1.49 +/- 0.07 (stat) +/- 0.53 (syst) and 2.36 +/- 0.09 (stat) +/- 0.47(syst), respectively. This corresponds to an excess of more than five standard deviations over the expected background. The present result constitutes the first observation of proton-tagged gamma gamma collisions at the electroweak scale. This measurement also demonstrates that CT-PPS performs according to the design specifications. Show less

Date Issued

2018-07-24

Identifier

FSU_libsubv1_wos_000440090400002, 10.1007/JHEP07(2018)153

Format

Citation

Title

Search For T(t)over-barh Production In The All-jet Final State In Proton-proton Collisions Root S=13 Tev.

A search is presented for the associated production of a Higgs boson with a top quark pair in the all-jet final state. Events containing seven or more jets are selected from a sample of proton-proton collisions at root s = 13 TeV collected with the CMS detector at the LHC in 2016, corresponding to an integrated luminosity of 35.9 fb(-1). To separate the t (t) over barH signal from the irreducible t (t) over bar + b (b) over bar background, the analysis assigns leading order matrix element... Show moreA search is presented for the associated production of a Higgs boson with a top quark pair in the all-jet final state. Events containing seven or more jets are selected from a sample of proton-proton collisions at root s = 13 TeV collected with the CMS detector at the LHC in 2016, corresponding to an integrated luminosity of 35.9 fb(-1). To separate the t (t) over barH signal from the irreducible t (t) over bar + b (b) over bar background, the analysis assigns leading order matrix element signal and background probability densities to each event. A likelihood-ratio statistic based on these probability densities is used to extract the signal. The results are provided in terms of an observed t (t) over barH signal strength relative to the standard model production cross section mu = sigma/sigma(SM), assuming a Higgs boson mass of 125 GeV. The best fit value is (mu) over cap = 0.9 +/- 0.7(stat) +/- 1.3(syst) = 0.9 +/- 1.5 (tot), and the observed and expected upper limits are, respectively, mu < 3.8 and < 3.1 at 95% confidence levels. Show less

Date Issued

2018-06-20

Identifier

FSU_libsubv1_wos_000436004000010, 10.1007/JHEP06(2018)101

Format

Citation

Title

Measurement of differential and integrated fiducial cross sections for Higgs boson production in the four-lepton decay channel in pp collisions at root s=7 and 8 TeV.

Integrated fiducial cross sections for the production of four leptons via the H -> 4l decays (l = e, mu) are measured in pp collisions at root s = 7 and 8TeV. Measurements are performed with data corresponding to integrated luminosities of 5.1 fb(-1) at 7TeV, and 19.7 fb(-1) at 8 TeV, collected with the CMS experiment at the LHC. Differential cross sections are measured using the 8 TeV data, and are determined as functions of the transverse momentum and rapidity of the four-lepton system,... Show moreIntegrated fiducial cross sections for the production of four leptons via the H -> 4l decays (l = e, mu) are measured in pp collisions at root s = 7 and 8TeV. Measurements are performed with data corresponding to integrated luminosities of 5.1 fb(-1) at 7TeV, and 19.7 fb(-1) at 8 TeV, collected with the CMS experiment at the LHC. Differential cross sections are measured using the 8 TeV data, and are determined as functions of the transverse momentum and rapidity of the four-lepton system, accompanying jet multiplicity, transverse momentum of the leading jet, and difference in rapidity between the Higgs boson candidate and the leading jet. A measurement of the Z -> 4l cross section, and its ratio to the H -> 4l cross section is also performed. All cross sections are measured within a fiducial phase space defined by the requirements on lepton kinematics and event topology. The integrated H -> 4l fiducial cross section is measured to be 0.56-(+0.67)(0.44) (stat) (+0.21)(-0.06) (syst) fb at 7 TeV, and 1.11(-0.35)(+ 0.41) (stat) (+ 0.14)(-0.10) (syst) fb at 8 TeV. The measurements are found to be compatible with theoretical calculations based on the standard model. Show less

Date Issued

2016-04-01

Identifier

FSU_libsubv1_wos_000373638000001, 10.1007/JHEP04(2016)005

Format

Citation

Title

Measurement Of The Top Quark Mass Using Proton-proton Data At Root(s)=7.

A new set of measurements of the top quark mass are presented, based on the proton-proton data recorded by the CMS experiment at the LHC at root s = 8 TeV corresponding to a luminosity of 19.7 fb(-1). The top quark mass is measured using the lepton + jets, all-jets and dilepton decay channels, giving values of 172.35 +/- 0.16(stat) +/- 0.48(syst) GeV, 172.32 +/- 0.25(stat) +/- 0.59(syst) GeV, and 172.82 +/- 0.19(stat) +/- 1.22(syst) GeV, respectively. When combined with the published CMS... Show moreA new set of measurements of the top quark mass are presented, based on the proton-proton data recorded by the CMS experiment at the LHC at root s = 8 TeV corresponding to a luminosity of 19.7 fb(-1). The top quark mass is measured using the lepton + jets, all-jets and dilepton decay channels, giving values of 172.35 +/- 0.16(stat) +/- 0.48(syst) GeV, 172.32 +/- 0.25(stat) +/- 0.59(syst) GeV, and 172.82 +/- 0.19(stat) +/- 1.22(syst) GeV, respectively. When combined with the published CMS results at s = 7 TeV, they provide a top quark mass measurement of 172.44 +/- 0.13(stat) +/- 0.47(syst) GeV. The top quark mass is also studied as a function of the event kinematical properties in the lepton + jets decay channel. No indications of a kinematic bias are observed and the collision data are consistent with a range of predictions from current theoretical models of t (t) over bar production. Show less

Date Issued

2016-04-07

Identifier

FSU_libsubv1_wos_000373578900001, 10.1103/PhysRevD.93.072004

Format

Citation

Title

Measurement Of The Top Quark Mass Using Charged Particles In Pp Collisions At Root S=8 Tev.

A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 fb(-1). By reconstructing secondary vertices inside the selected jets and computing the invariant mass of the system formed by the secondary vertex... Show moreA novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 fb(-1). By reconstructing secondary vertices inside the selected jets and computing the invariant mass of the system formed by the secondary vertex and an isolated lepton, an observable is constructed that is sensitive to the top quark mass that is expected to be robust against the energy scale of hadronic jets. The main theoretical systematic uncertainties, concerning the modeling of the fragmentation and hadronization of b quarks and the reconstruction of secondary vertices from the decays of b hadrons, are studied. A top quark mass of 173.68 +/- 0.20(stat)(-0.97)(+1.58) (syst) GeV is measured. The overall systematic uncertainty is dominated by the uncertainty in the b quark fragmentation and the modeling of kinematic properties of the top quark. Show less

Date Issued

2016-05-18

Identifier

FSU_libsubv1_wos_000376255900001, 10.1103/PhysRevD.93.092006

Format

Citation

Title

Observation Of Charge-dependent Azimuthal Correlations In P-pb Collisions And Its Implication For The Search For The Chiral Magnetic Effect.

Charge-dependent azimuthal particle correlations with respect to the second-order event plane in p-Pb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range broken vertical bar eta broken vertical bar
Show moreCharge-dependent azimuthal particle correlations with respect to the second-order event plane in p-Pb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range broken vertical bar eta broken vertical bar < 2.4, and a third particle measured in the hadron forward calorimeters (4.4 < broken vertical bar eta broken vertical bar < 5). The observed differences between the same and opposite sign correlations, as functions of multiplicity and. gap between the two charged particles, are of similar magnitude in p-Pb and PbPb collisions at the same multiplicities. These results pose a challenge for the interpretation of charge-dependent azimuthal correlations in heavy ion collisions in terms of the chiral magnetic effect. Show less

Date Issued

2017-03-24

Identifier

FSU_libsubv1_wos_000397805800005, 10.1103/PhysRevLett.118.122301

Format

Citation

Title

Search For Heavy Gauge W ' Bosons In Events With An Energetic Lepton And Large Missing Transverse Momentum At Root S=13tev.

A search is presented for W' bosons in events with an electron or muon and large missing transverse momentum, using proton-proton collision data at root s = 13 TeV collected with the CMS detector in 2015 and corresponding to an integrated luminosity of 2.3 fb(-1). No evidence of an excess of events relative to the standard model expectations is observed. For a W' boson described by the sequential standard model, upper limits at 95% confidence level are set on the product of the production... Show moreA search is presented for W' bosons in events with an electron or muon and large missing transverse momentum, using proton-proton collision data at root s = 13 TeV collected with the CMS detector in 2015 and corresponding to an integrated luminosity of 2.3 fb(-1). No evidence of an excess of events relative to the standard model expectations is observed. For a W' boson described by the sequential standard model, upper limits at 95% confidence level are set on the product of the production cross section and branching fraction and lower limits are established on the new boson mass. Masses below 4.1 TeV are excluded combining electron and muon decay channels, significantly improving upon the results obtained with the 8 TeV data. Exclusion limits at 95% confidence level on the product of the W' production cross section and branching fraction are also derived in combination with the 8 TeV data. Finally, exclusion limits are set for the production of generic W' bosons decaying into this final state using a model-independent approach. (C) 2017 The Author. Published by Elsevier B.V. Show less

Date Issued

2017-07-10

Identifier

FSU_libsubv1_wos_000404196500039, 10.1016/j.physletb.2017.04.043

Format

Citation

Title

Search For Supersymmetry In The Multijet And Missing Transverse Momentum Final State In Pp Collisions At 13 Tev.

A search for new physics is performed based on all-hadronic events with large missing transverse momentum produced in proton-proton collisions at root s = 13 TeV. The data sample, corresponding to an integrated luminosity of 2.3 fb(-1), was collected with the CMS detector at the CERN LHC in 2015. The data are examined in search regions of jet multiplicity, tagged bottom quark jet multiplicity, missing transverse momentum, and the scalar sum of jet transverse momenta. The observed numbers of... Show moreA search for new physics is performed based on all-hadronic events with large missing transverse momentum produced in proton-proton collisions at root s = 13 TeV. The data sample, corresponding to an integrated luminosity of 2.3 fb(-1), was collected with the CMS detector at the CERN LHC in 2015. The data are examined in search regions of jet multiplicity, tagged bottom quark jet multiplicity, missing transverse momentum, and the scalar sum of jet transverse momenta. The observed numbers of events in all search regions are found to be consistent with the expectations from standard model processes. Exclusion limits are presented for simplified supersymmetric models of gluino pair production. Depending on the assumed gluino decay mechanism, and for a massless, weakly interacting, lightest neutralino, lower limits on the gluino mass from 1440 to 1600 GeV are obtained, significantly extending previous limits. (C) 2016 The Author. Published by Elsevier B.V. Show less

Date Issued

2016-07-10

Identifier

FSU_libsubv1_wos_000377330500025, 10.1016/j.physletb.2016.05.002

Format

Citation

Title

Suppression Of Gamma(1s), Gamma(2s), And Gamma(3s) Quarkonium States In Pbpb Collisions At Root S-nn=2.76tev.

The production yields of gamma(1S), gamma(2S), and gamma(3S) quarkonium states are measured through their decays into muon pairs in the CMS detector, in PbPb and pp collisions at the centre-of-mass energy per nucleon pair of 2.76TeV. The data correspond to integrated luminosities of 166 mu b(-1) and 5.4 pb(-1) for PbPb and pp collisions, respectively. Differential production cross sections are reported as functions of gamma rapidity y up to 2.4, and transverse momentum PT up to 20 GeV/c. A... Show moreThe production yields of gamma(1S), gamma(2S), and gamma(3S) quarkonium states are measured through their decays into muon pairs in the CMS detector, in PbPb and pp collisions at the centre-of-mass energy per nucleon pair of 2.76TeV. The data correspond to integrated luminosities of 166 mu b(-1) and 5.4 pb(-1) for PbPb and pp collisions, respectively. Differential production cross sections are reported as functions of gamma rapidity y up to 2.4, and transverse momentum PT up to 20 GeV/c. A strong centrality-dependent suppression is observed in PbPb relative to pp collisions, by factors of up to approximate to 2 and 8, for the gamma(1S) and gamma(2S) states, respectively. No significant dependence of this suppression is observed as a function of y or PT. The gamma(3S) state is not observed in PbPb collisions, which corresponds to a suppression for the centrality-integrated data by at least a factor of approximate to 7 at a 95% confidence level. The observed suppression is in agreement with theoretical scenarios modeling the sequential melting of quarkonium states in a quark gluon plasma. (C) 2017 The Author(s). Published by Elsevier B.V. Show less

Date Issued

2017-07-10

Identifier

FSU_libsubv1_wos_000404196500050, 10.1016/j.physletb.2017.04.031

Format

Citation

Title

Measurement of the differential cross section and charge asymmetry for inclusive [Formula: see text] production at [Formula.

The differential cross section and charge asymmetry for inclusive [Formula: see text] production at [Formula: see text] are measured as a function of muon pseudorapidity. The data sample corresponds to an integrated luminosity of 18.8[Formula: see text] recorded with the CMS detector at the LHC. These results provide important constraints on the parton distribution functions of the proton in the range of the Bjorken scaling variable from [Formula: see text] to [Formula: see text].

The pseudorapidity distributions of dijets as functions of their average transverse momentum (p(T)(ave)) are measured in proton-lead (pPb) and proton-proton (pp) collisions. The data samples were collected by the CMS experiment at the CERN LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV. A significant modification of the pPb spectra with respect to the pp spectra is observed in all p(T)(ave) intervals investigated. The ratios of the pPb and pp distributions are compared to next-to... Show moreThe pseudorapidity distributions of dijets as functions of their average transverse momentum (p(T)(ave)) are measured in proton-lead (pPb) and proton-proton (pp) collisions. The data samples were collected by the CMS experiment at the CERN LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV. A significant modification of the pPb spectra with respect to the pp spectra is observed in all p(T)(ave) intervals investigated. The ratios of the pPb and pp distributions are compared to next-to-leading order perturbative quantum chromodynamics calculations with unbound nucleon and nuclear parton distribution functions (PDFs). These results give the first evidence that the gluon PDF at large Bjorken x in lead ions is strongly suppressed with respect to the PDF in unbound nucleons. Show less

Date Issued

2018-08-07

Identifier

FSU_libsubv1_wos_000441021400008, 10.1103/PhysRevLett.121.062002

Format

Citation

Title

Constraints On Models Of Scalar And Vector Leptoquarks Decaying To A Quark And A Neutrino At Root S=13 Tev.

The results of a previous search by the CMS Collaboration for squarks and gluinos are reinterpreted to constrain models of leptoquark (LQ) production. The search considers jets in association with a transverse momentum imbalance, using the M-T2 variable. The analysis uses proton-proton collision data at root s = 13 TeV, recorded with the CMS detector at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb(-1). Leptoquark pair production is considered with LQ decays to a... Show moreThe results of a previous search by the CMS Collaboration for squarks and gluinos are reinterpreted to constrain models of leptoquark (LQ) production. The search considers jets in association with a transverse momentum imbalance, using the M-T2 variable. The analysis uses proton-proton collision data at root s = 13 TeV, recorded with the CMS detector at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb(-1). Leptoquark pair production is considered with LQ decays to a neutrino and a top, bottom, or light quark. This reinterpretation considers higher mass values than the original CMS search to constrain both scalar and vector LQs. Limits on the cross section for LQ pair production are derived at the 95% confidence level depending on the LQ decay mode. A vector LQ decaying with a 50% branching fraction to t nu, and 50% to b tau, has been proposed as part of an explanation of anomalous flavor physics results. In such a model, using only the decays to t nu, LQ masses below 1530 GeV are excluded assuming the Yang-Mills case with coupling kappa = 1, or 1115 GeV in the minimal coupling case kappa = 0, placing the most stringent constraint to date from pair production of vector LQs. Show less

Date Issued

2018-08-10

Identifier

FSU_libsubv1_wos_000441334500002, 10.1103/PhysRevD.98.032005

Format

Citation

Title

Search For Additional Neutral Mssm Higgs Bosons In The Tau Tau Final State In Proton-proton Collisions At Root S=13 Tev.

A search is presented for additional neutral Higgs bosons in the tau tau final state in proton-proton collisions at the LHC. The search is performed in the context of the minimal supersymmetric extension of the standard model (MSSM), using the data collected with the CMS detector in 2016 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes production of the Higgs boson in... Show moreA search is presented for additional neutral Higgs bosons in the tau tau final state in proton-proton collisions at the LHC. The search is performed in the context of the minimal supersymmetric extension of the standard model (MSSM), using the data collected with the CMS detector in 2016 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes production of the Higgs boson in association with b quarks. No significant deviation above the expected background is observed. Model-independent limits at 95% confidence level (CL) are set on the product of the branching fraction for the decay into tau leptons and the cross section for the production via gluon fusion or in association with b quarks. These limits range from 18 pb at 90 GeV to 3.5 fb at 3.2 TeV for gluon fusion and from 15 pb (at 90 GeV) to 2.5 fb (at 3.2TeV) for production in association with b quarks, assuming a narrow width resonance. In the m(h)(mod+) scenario these limits translate into a 95% CL exclusion of tan beta > 6 for neutral Higgs boson masses below 250 GeV, where tan beta is the ratio of the vacuum expectation values of the neutral components of the two Higgs doublets. The 95% CL exclusion contour reaches 1.6TeV for tan beta = 60. Show less

Date Issued

2018-09-03

Identifier

FSU_libsubv1_wos_000443816700001, 10.1007/JHEP09(2018)007

Format

Citation

Title

Measurement of t(t)over-bar production with additional jet activity, including b quark jets, in the dilepton decay channel using pp collisions at root s=8TeV.

Jet multiplicity distributions in top quark pair (t (t) over bar) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7 fb(-1). The measurement is performed in the dilepton decay channels (e(+)e(-), mu(+)mu(-), and e(+/-)mu(+/-)). The absolute and normalized differential cross sections for t (t) over bar production are measured as a function of the jet multiplicity in the... Show moreJet multiplicity distributions in top quark pair (t (t) over bar) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7 fb(-1). The measurement is performed in the dilepton decay channels (e(+)e(-), mu(+)mu(-), and e(+/-)mu(+/-)). The absolute and normalized differential cross sections for t (t) over bar production are measured as a function of the jet multiplicity in the event for different jet transverse momentum thresholds and the kinematic properties of the leading additional jets. The differential t (t) over barb and t (t) over barb (b) over bar cross sections are presented for the first time as a function of the kinematic properties of the leading additional b jets. Furthermore, the fraction of events without additional jets above a threshold is measured as a function of the transverse momenta of the leading additional jets and the scalar sum of the transverse momenta of all additional jets. The data are compared and found to be consistent with predictions from several perturbative quantum chromodynamics event generators and a next-to-leading order calculation. Show less

Inclusive jet spectra from pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV, collected with the CMS detector at the CERN Large Hadron Collider, are presented. Jets are reconstructed with three different distance parameters (R = 0.2, 0.3, and 0.4) for transverse momentum (p(T)) greater than 70 GeV/c and pseudorapidity |eta|
Show moreInclusive jet spectra from pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV, collected with the CMS detector at the CERN Large Hadron Collider, are presented. Jets are reconstructed with three different distance parameters (R = 0.2, 0.3, and 0.4) for transverse momentum (p(T)) greater than 70 GeV/c and pseudorapidity |eta| < 2. Next-to-leading-order quantum chromodynamic calculations with nonperturbative corrections are found to overpredict jet production cross sections in pp for small distance parameters. The jet nuclear modification factors for PbPb compared to pp collisions, show a steady decrease from peripheral to central events, along with a weak dependence on the jet p(T). They are found to be independent of the distance parameter in the measured kinematic range. Show less

Date Issued

2017-07-17

Identifier

FSU_libsubv1_wos_000405709100007, 10.1103/PhysRevC.96.015202

Format

Citation

Title

Measurements Of Differential Production Cross Sections For A Z Boson In Association With Jets In Pp Collisions At Root S=8 Tev.

Cross sections for the production of a Z boson in association with jets in proton-proton collisions at a centre-of-mass energy of root s = 8 TeV are measured using a data sample collected by the CMS experiment at the LHC corresponding to 19.6 fb(-1). Differential cross sections are presented as functions of up to three observables that describe the jet kinematics and the jet activity. Correlations between the azimuthal directions and the rapidities of the jets and the Z boson are studied in... Show moreCross sections for the production of a Z boson in association with jets in proton-proton collisions at a centre-of-mass energy of root s = 8 TeV are measured using a data sample collected by the CMS experiment at the LHC corresponding to 19.6 fb(-1). Differential cross sections are presented as functions of up to three observables that describe the jet kinematics and the jet activity. Correlations between the azimuthal directions and the rapidities of the jets and the Z boson are studied in detail. The predictions of a number of multileg generators with leading or next-to-leading order accuracy are compared with the measurements. The comparison shows the importance of including multi-parton contributions in the matrix elements and the improvement in the predictions when nextto- leading order terms are included. Show less

Date Issued

2017-04-05

Identifier

FSU_libsubv1_wos_000398450300001, 10.1007/JHEP04(2017)022

Format

Citation

Title

Search for Higgs boson off-shell production in proton-proton collisions at 7 and 8 TeV and derivation of constraints on its total decay width.